Noise only in 6th gear

Yes!! (Saw your post after I posted mine, sorry!)

 

LOL it's all good.

Just for fun, this is an interesting read, or I think so anyway.

http://www.explainthatstuff.com/gears.html

 

Thanks for the replies.

Yes, I have checked the oil level. It was not low, if anything it may have been a little high. When I removed the side fill plug, a steady stream of oil came out. I'd say a few ounces worth maybe. I was parked on a flat surface, so I just let it drain down and then put the plug back in. Color was a golden brown, about like engine oil.

I have on my list of to-dos to find some Redline MT90 and put that in there.

 

Wow, that's pretty close to what mine sounds like. Yours might be a little higher pitched than mine, but very similar. And mine starts immediately when I shift into 6th. I don't have to wait to get up to 60mph for it to start singing.

 

Thanks. So would a bad bearing get quieter after I drive it for 20minutes or so? It doesn't completely disappear, but it's definitely quieter.

Also, just to clarify. My mystery noise is not a squeal. It's more like a well-defined higher pitched hum, with a frequency of around 500Hz (maybe).

 

Mine has the slight hum of a supercharger, it's not loud at all -- very faint actually, while pulling hills in 6th gear. I don't hear it driving on level highway or road in 6th. Sounds a lot like the video. I don't believe it to be anything concerning.

 

Well, just to update. I changed the fluid in the transmission and transfer case to Redline MT90. Have been impressed so far with how much better it shifts. Much smoother. But the mystery noise is still there. But I'm trying to convince myself it is a little quieter now. Hard to tell.

A few days ago (before Redline), when I left work it was 95degrees outside. And the mystery noise was much quieter. So faint I had to really listen to know it was there. But the next morning, at 65degrees, it was back. That afternoon, back to 90degrees. And it was much quieter again. Still there, but much quieter.

I don't get it. This WEEEEEENNNNNN is driving me nuts!!

 

Too thick perhaps?

 

I think you'll have to get used to it, bud. You've done all you reasonably can. Have you held the stick to the left or right, held it back to the rear of the truck? I suppose it's possible the linkage is vibrating . . . .

 

Yep. I've pushed it left, right, forward, rear. Can't tell it makes any difference. It's only in 6th gear (at any speed, although around 50mph seems worse), and the only things I've found that seem to affect the noise and make it a little quieter are 1) drive for about 20minutes or so, or 2) it's really hot outside. In both cases the noise is still there, but much quieter. It never completely goes away. I still think the outside temperature is the biggest player so far.

Any chance its drive shaft related? Or some other metal component that's singing? I'm thinking if the metal is hotter, maybe it doesn't resonate as much. Just a wild guess there (I'm getting desperate).

 

Holy crap that's the same noise I have in 5th with my 2012 RC MT 5-spd,

and Toyota is telling me it's normal. :-(